@article{EngelmannBuhlBaumannetal.2017, author = {Engelmann, Ulrich M. and Buhl, Eva Miriam and Baumann, Martin and Schmitz-Rode, Thomas and Slabu, Ioana}, title = {Agglomeration of magnetic nanoparticles and its effects on magnetic hyperthermia}, series = {Current Directions in Biomedical Engineering}, volume = {3}, journal = {Current Directions in Biomedical Engineering}, number = {2}, publisher = {De Gruyter}, address = {Berlin}, issn = {2364-5504}, doi = {10.1515/cdbme-2017-0096}, pages = {457 -- 460}, year = {2017}, language = {en} } @article{EngelmannBuhlDraacketal.2018, author = {Engelmann, Ulrich M. and Buhl, Eva Miriam and Draack, Sebastian and Viereck, Thilo and Frank, and Schmitz-Rode, Thomas and Slabu, Ioana}, title = {Magnetic relaxation of agglomerated and immobilized iron oxide nanoparticles for hyperthermia and imaging applications}, series = {IEEE Magnetic Letters}, volume = {9}, journal = {IEEE Magnetic Letters}, number = {Article number 8519617}, publisher = {IEEE}, address = {New York, NY}, issn = {1949-307X}, doi = {10.1109/LMAG.2018.2879034}, year = {2018}, abstract = {Magnetic nanoparticles (MNPs) are used as therapeutic and diagnostic agents for local delivery of heat and image contrast enhancement in diseased tissue. Besides magnetization, the most important parameter that determines their performance for these applications is their magnetic relaxation, which can be affected when MNPs immobilize and agglomerate inside tissues. In this letter, we investigate different MNP agglomeration states for their magnetic relaxation properties under excitation in alternating fields and relate this to their heating efficiency and imaging properties. With focus on magnetic fluid hyperthermia, two different trends in MNP heating efficiency are measured: an increase by up to 23\% for agglomerated MNP in suspension and a decrease by up to 28\% for mixed states of agglomerated and immobilized MNP, which indicates that immobilization is the dominant effect. The same comparatively moderate effects are obtained for the signal amplitude in magnetic particle spectroscopy.}, language = {en} } @article{EngelmannRoethEberbecketal.2018, author = {Engelmann, Ulrich M. and Roeth, Anjali A.J. and Eberbeck, Dietmar and Buhl, Eva Miriam and Neumann, Ulf Peter and Schmitz-Rode, Thomas and Slabu, Ioana}, title = {Combining Bulk Temperature and Nanoheating Enables Advanced Magnetic Fluid Hyperthermia Efficacy on Pancreatic Tumor Cells}, series = {Scientific Reports}, volume = {8}, journal = {Scientific Reports}, number = {1}, publisher = {Springer Nature}, address = {Cham}, issn = {2045-2322}, doi = {10.1038/s41598-018-31553-9}, pages = {Article number 13210}, year = {2018}, abstract = {Many efforts are made worldwide to establish magnetic fluid hyperthermia (MFH) as a treatment for organ-confined tumors. However, translation to clinical application hardly succeeds as it still lacks of understanding the mechanisms determining MFH cytotoxic effects. Here, we investigate the intracellular MFH efficacy with respect to different parameters and assess the intracellular cytotoxic effects in detail. For this, MiaPaCa-2 human pancreatic tumor cells and L929 murine fibroblasts were loaded with iron-oxide magnetic nanoparticles (MNP) and exposed to MFH for either 30 min or 90 min. The resulting cytotoxic effects were assessed via clonogenic assay. Our results demonstrate that cell damage depends not only on the obvious parameters bulk temperature and duration of treatment, but most importantly on cell type and thermal energy deposited per cell during MFH treatment. Tumor cell death of 95\% was achieved by depositing an intracellular total thermal energy with about 50\% margin to damage of healthy cells. This is attributed to combined intracellular nanoheating and extracellular bulk heating. Tumor cell damage of up to 86\% was observed for MFH treatment without perceptible bulk temperature rise. Effective heating decreased by up to 65\% after MNP were internalized inside cells.}, language = {en} } @article{EngelmannSeifertMuesetal.2019, author = {Engelmann, Ulrich M. and Seifert, Julian and Mues, Benedikt and Roitsch, Stefan and M{\´e}nager, Christine and Schmidt, Annette M. and Slabu, Ioana}, title = {Heating efficiency of magnetic nanoparticles decreases with gradual immobilization in hydrogels}, series = {Journal of Magnetism and Magnetic Materials}, volume = {471}, journal = {Journal of Magnetism and Magnetic Materials}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0304-8853}, doi = {10.1016/j.jmmm.2018.09.113}, pages = {486 -- 494}, year = {2019}, language = {en} } @article{EngelmannShashaTeemanetal.2019, author = {Engelmann, Ulrich M. and Shasha, Carolyn and Teeman, Eric and Slabu, Iona and Krishnan, Kannan M.}, title = {Predicting size-dependent heating efficiency of magnetic nanoparticles from experiment and stochastic N{\´e}el-Brown Langevin simulation}, series = {Journal of Magnetism and Magnetic Materials}, volume = {471}, journal = {Journal of Magnetism and Magnetic Materials}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0304-8853}, doi = {10.1016/j.jmmm.2018.09.041}, pages = {450 -- 456}, year = {2019}, language = {en} } @article{SlabuRoethEngelmannetal.2019, author = {Slabu, Ioana and Roeth, Anjali A. and Engelmann, Ulrich M. and Wiekhorst, Frank and Buhl, Eva M. and Neumann, Ulf P. and Schmitz-Rode, Thomas}, title = {Modeling of magnetoliposome uptake in human pancreatic tumor cells in vitro}, series = {Nanotechnology}, volume = {30}, journal = {Nanotechnology}, number = {18}, issn = {1361-6528}, doi = {10.1088/1361-6528/ab033e}, pages = {184004}, year = {2019}, language = {en} } @article{EngelGemuendeHoltmannetal.2019, author = {Engel, Mareike and Gem{\"u}nde, Andre and Holtmann, Dirk and M{\"u}ller-Renno, Christine and Ziegler, Christiane and Tippk{\"o}tter, Nils and Ulber, Roland}, title = {Clostridium acetobutylicum's connecting world: cell appendage formation in bioelectrochemical systems}, series = {ChemElectroChem}, volume = {7}, journal = {ChemElectroChem}, number = {2}, publisher = {Wiley}, address = {Weinheim}, issn = {2196-0216}, doi = {10.1002/celc.201901656}, pages = {414 -- 420}, year = {2019}, abstract = {Bacterial cell appendix formation supports cell-cell interaction, cell adhesion and cell movement. Additionally, in bioelectrochemical systems (BES), cell appendages have been shown to participate in extracellular electron transfer. In this work, the cell appendix formation of Clostridium acetobutylicum in biofilms of a BES are imaged and compared with conventional biofilms. Under all observed conditions, the cells possess filamentous appendages with a higher number and density in the BES. Differences in the amount of extracellular polymeric substance in the biofilms of the electrodes lead to the conclusion that the cathode can be used as electron donor and the anode as electron acceptor by C. acetobutylicum. When using conductive atomic force microscopy, a current response of about 15 nA is found for the cell appendages from the BES. This is the first report of conductivity for clostridial cell appendices and represents the basis for further studies on their role for biofilm formation and electron transfer.}, language = {en} } @article{DigelAkimbekovTuralievaetal.2013, author = {Digel, Ilya and Akimbekov, Nuraly S. and Turalieva, M. and Mansurov, Z. and Temiz Artmann, Ayseg{\"u}l and Eshibaev, A. and Zhubanova, A.}, title = {Usage of Carbonized Plant Wastes for Purification of Aqueous Solutions}, series = {Journal of Industrial Technology and Engineering}, volume = {2}, journal = {Journal of Industrial Technology and Engineering}, number = {07}, pages = {47 -- 54}, year = {2013}, language = {en} } @article{KarschuckFilipovBollellaetal.2019, author = {Karschuck, T. L. and Filipov, Y. and Bollella, P. and Sch{\"o}ning, Michael Josef and Katz, E.}, title = {Not-XOR (NXOR) logic gate based on an enzyme-catalyzed reaction}, series = {International Journal of Unconventional Computing}, volume = {14}, journal = {International Journal of Unconventional Computing}, number = {3-4}, publisher = {Old City Publishing}, address = {Philadelphia}, issn = {1548-7199}, pages = {235 -- 242}, year = {2019}, abstract = {Enzyme-catalyzed reactions have been designed to mimic various Boolean logic gates in the general framework of unconventional biomolecular computing. While some of the logic gates, particularly OR, AND, are easy to realize with biocatalytic reactions and have been reported in numerous publications, some other, like NXOR, are very challenging and have not been realized yet with enzyme reactions. The paper reports on a novel approach to mimicking the NXOR logic gate using the bell-shaped enzyme activity dependent on pH values. Shifting pH from the optimum value to the acidic or basic values by using acid or base inputs (meaning 1,0 and 0,1 inputs) inhibits the enzyme reaction, while keeping the optimum pH (assuming 0,0 and 1,1 input combinations) preserves a high enzyme activity. The challenging part of the present approach is the selection of an enzyme with a well-demonstrated bell-shape activity dependence on the pH value. While many enzymes can satisfy this condition, we selected pyrroloquinoline quinone (PQQ)-dependent glucose dehydrogenase as this enzyme has the optimum pH center-located on the pH scale allowing the enzyme activity change by the acidic and basic pH shift from the optimum value corresponding to the highest activity. The present NXOR gate is added to the biomolecular "toolbox" as a new example of Boolean logic gates based on enzyme reactions.}, language = {en} } @article{DantismRoehlenWagneretal.2019, author = {Dantism, Shahriar and R{\"o}hlen, Desiree and Wagner, Torsten and Wagner, P. and Sch{\"o}ning, Michael Josef}, title = {A LAPS-based differential sensor for parallelized metabolism monitoring of various bacteria}, series = {Sensors}, volume = {19}, journal = {Sensors}, number = {21}, publisher = {MDPI}, address = {Basel}, issn = {1424-8220}, doi = {10.3390/s19214692}, pages = {Artikel 4692}, year = {2019}, abstract = {Monitoring the cellular metabolism of bacteria in (bio)fermentation processes is crucial to control and steer them, and to prevent undesired disturbances linked to metabolically inactive microorganisms. In this context, cell-based biosensors can play an important role to improve the quality and increase the yield of such processes. This work describes the simultaneous analysis of the metabolic behavior of three different types of bacteria by means of a differential light-addressable potentiometric sensor (LAPS) set-up. The study includes Lactobacillus brevis, Corynebacterium glutamicum, and Escherichia coli, which are often applied in fermentation processes in bioreactors. Differential measurements were carried out to compensate undesirable influences such as sensor signal drift, and pH value variation during the measurements. Furthermore, calibration curves of the cellular metabolism were established as a function of the glucose concentration or cell number variation with all three model microorganisms. In this context, simultaneous (bio)sensing with the multi-organism LAPS-based set-up can open new possibilities for a cost-effective, rapid detection of the extracellular acidification of bacteria on a single sensor chip. It can be applied to evaluate the metabolic response of bacteria populations in a (bio)fermentation process, for instance, in the biogas fermentation process.}, language = {en} }